The present invention relates to a method for producing a hollow profile having a curved portion which has a centre of curvature, wherein a blank is preshaped to form a U-shaped profile by introducing a punch into a first die and the U-shaped profile is shaped with a second die to form an O-shaped profile having at least one longitudinal slot. The invention also relates to a support core for carrying out the method. Finally, the subject-matter of the invention is also a hollow profile having a curved portion which has a centre of curvature.
A method for producing a hollow profile having a curved portion is described, for example, in DE 10 2004 025 857 A1. In the known method, there is first produced a flat blank which has a first elongate region, an adjacent transition region and a second elongate region which is adjacent thereto. A first longitudinal centre line of the first region extends in this instance in an angled manner with respect to a second longitudinal centre line of the second elongate region. The material pre-cut is then preshaped along the first region, the transition region and the second region to form a U-shaped profile which extends in the longitudinal direction in a rounded angular manner and which has limbs of substantially the same length. Subsequently, the U-shaped profile is further shaped to form an O-shaped profile and the adjacent edges of the O-shaped profile located centrally at the highest point are welded together. It has been found that, with the production of particularly more greatly curved hollow bodies with the known method, cracks or folds may occur in the curved portion.